Ford 3000 Overheat

On a 1970 Ford 3000, 3 cyl. gas, with an FEL, trans 8F and 2R having overtemp problems. It sat for quite some time and needed a carb rebuild.
That done, it runs well now. Runs smooth and has good power. I will also check the timing and verify the under carb gasket to see if it is sucking in air. But either idling for some time or putting it to work will gradually overtemp, with the FEL and loaded rear tires it is heavy just moving around. Once when idling for a long period it shut down on it's own. Let it cool down starts right back up. Appears to have good coolant flow. I know it is missing the vacuum advance line from carb to intake and will replace that shortly. It looks like a very short metal line, could I use teflon or just metal??
I will check or replace the thermostat, and back flush the radiator fins. I have a solid state ignition kit for it I will do soon too.

Re: Ford 3000 Overheat

Vaccum advance line can be almost anything. Most cars use rubber. Check the air flow throught the radiator. You should be able to put a light on one side and see it from the other. Also check fan belt tension, loose belt can cause overheating. If it has an oil cooler you can get dirt between the cooler and the radiator that you cannot see easily.

Re: Ford 3000 Overheat

Seems to have good power and runs smooth. Holley Carb had a complete rebuild. Originally, bowl and everything was gummed up and green. I will have to re-check the mixture and plugs.
I did have the lower rad hose collapse, replaced with a new reinforced one. What generally causes that?